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The Physics of Rigid Body Rotations: Three Methods to Model a Tumbling Object in Python.
One of my favorite (and simple) physics demonstrations is to show that angular momentum and angular velocity don’t have to be in the same direction. You can do this demo on your own.
Take a rectangular cubic object (I’m going to use a chalkboard eraser) and toss it into the air so that it flips. Once the object leaves your hand, the only force acting on it is the gravitational force such that there is no external torque (about the center of mass). This means that it must have a constant angular momentum. However, as you can see the object tumbles which means it DOES NOT have a constant angular velocity. Check it out.
But now we are left with the important question: how can we model this motion? Yes, just like the title says — I’m going to go over three different methods to make this work (with python).
Masses and Springs
From a certain point of view, angular momentum is redundant. If you have a bunch of individual masses that make up a rigid body, you can just calculate the force on each mass and use that force to update the momentum for…
